Chemical Pinning to Direct Addressable Array Using Self-Assembling Materials

ABSTRACT

A method includes: providing a substrate having a plurality of chemically contrasted alignment features, and depositing a self-assembled material on at least a portion of the substrate, wherein the position and/or orientation of substantially spherical or cylindrical domains of the self-assembled material is directed by the alignment features, to form a nanostructure pattern, and wherein the period of the alignment features is between about 2 times and about 10 times the period of the spherical or cylindrical domains. An apparatus fabricated according to the method is also provided.

BACKGROUND

Structures having components with dimensions on a nanometer scale arebeing considered for use in the areas of optics, electronics, mechanics,magnetism and so forth. Nanostructures encompass various structuresreferred to as, for example, nanoparticles, nanotubes or quantum dots,and may potentially be used as building blocks for ordered and complexmaterials.

For data storage media, including bit patterned media (BPM) and discretetrack media (DTM), the patterning of ultra-high density dot array orline array, with a periodicity as small as 25 nm or less is desirable.However, since optical lithography is limited by the diffraction limit,the resolution of conventional optical lithography is usually limited toabout 50 nm half-pitch. Thus conventional optical lithography may not besuitable for fabricating such nanostructures for bit patterned magneticstorage media.

A high-throughput patterning method is desired for formingnanostructures on a substrate. Self-assembly technology has thepotential to provide both ultrahigh-density patterning and highthroughput.

SUMMARY

In one aspect, the invention provides a method including: providing asubstrate having a plurality of chemically contrasted alignmentfeatures, and depositing a self-assembled material on at least a portionof the substrate, wherein the position and/or orientation ofsubstantially spherical domains of the self-assembled material isdirected by the alignment features, to form a nanostructure pattern, andwherein the period of the alignment features is between about 2 timesand about 10 times the period of the spherical domains.

In another aspect, the invention provides an apparatus including asubstrate having a plurality of chemically contrasted alignmentfeatures, and a self-assembled material on at least a portion of thesubstrate, wherein the position and/or orientation of substantiallyspherical domains of the self-assembled material is directed by thealignment features, to form a nanostructure pattern, and wherein theaverage spacing of the alignment features is between about 2 times andabout 10 times the period of the spherical domains.

In another aspect, the invention provides a method including: providinga substrate having a plurality of discrete chemically contrastedalignment features, and depositing a self-assembled material on at leasta portion of the plurality of chemically contrasted alignment features,wherein the position and/or orientation of substantially cylindricaldomains of the self-assembled material is directed by the alignmentfeatures, to form a laminar pattern, and wherein the period of thealignment features is between about 2 times and about 10 times theperiod of the cylindrical domains.

In another aspect, the invention provides an apparatus including asubstrate having a plurality of discrete chemically contrasted alignmentfeatures, and a self-assembled material on at least a portion of theplurality of chemically contrasted alignment features, wherein theposition and/or orientation of substantially cylindrical domains of theself-assembled material is directed by the alignment features, to form alaminar pattern, and wherein the average spacing of the alignmentfeatures is between about 2 times and about 10 times the period of thecylindrical domains.

In another aspect, the invention provides a method including: forming afirst plurality of spaced dots in a servo area of a substrate, using alithographic process to form a second plurality of spaced dots in a bitarea of a substrate, and depositing a self-assembled material on atleast a portion of the bit area, wherein the position and/or orientationof domains of the self-assembled material is directed by the secondplurality of spaced dots, to form a nanostructure pattern in the bitarea.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a fabrication process inaccordance with one aspect of the invention.

FIG. 2 is a schematic representation of a block copolymer.

FIG. 3 is a cross-sectional view of a substrate.

FIG. 4 is a cross-sectional view of a substrate.

FIGS. 5, 6 and 7 are schematic representations of dot patterns.

FIGS. 8, 9, 10 and 11 are schematic representations of portions ofpatterned media constructed in accordance with an aspect of theinvention.

FIG. 12 is a photomicrograph of a portion of a patterned media inaccordance with an aspect of the invention.

FIG. 13 is a schematic cross-sectional view of a portion of anotherpatterned media constructed in accordance with an aspect of theinvention.

FIG. 14 is a schematic cross-sectional view of a portion of anotherpatterned media constructed in accordance with an aspect of theinvention.

FIG. 15 is a photomicrograph of a portion of another patterned media inaccordance with an aspect of the invention.

FIG. 16 is a plan view of a patterned surface that can be used in thefabrication of the patterned media of FIG. 15.

FIGS. 17, 18 and 19 are schematic representations of a cross-section ofanother patterned media constructed in accordance with an aspect of theinvention.

FIG. 20 is a schematic representation of a data storage disc template inaccordance with an aspect of the invention.

FIG. 21 is a flow diagram that illustrates the method of an aspect ofthe invention.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to methods of fabricating nanostructured devicesand to devices fabricated using such methods. In one aspect, theinvention provides a method for achieving long-range order and precisepositional control in naturally self-assembled nanostructures.

The invention can be used in the fabrication of data storage media. Datastorage media generally includes a servo area and a bit area. The servoarea includes information that is used to control the position of arecording head and the timing of read and write operations. The bit areais used to store information that is written to and read from the media.In one aspect, the invention allows the integration of self-assemblyprocess into nanoimprint template fabrication of BPM for both a bit areahaving high-density periodic dot patterns and a servo area havingmedium-to-high density periodic/non-periodic dot/line patterns.

In another aspect, the invention uses a substrate structure with achemical contrast surface pattern that can be used to direct theself-assembly, or self-organization, of an array of nanostructures. Asused in this description, a chemical contrast substrate refers to asubstrate having regions or materials that exhibit different chemicalpreferences, or affinities, for different components of a blockcopolymer. The regions or materials can have little topographicdifference. The regions or materials serve as alignment features thatdirect the self-assembly of the nanostructures. Self-assembly means theformation of periodic nanostructures of self-assembling materials, suchas block copolymers and nanoparticles. The periodic nanostructures canform spontaneously in a relatively large area according to thermodynamicproperties.

A substrate having a chemical contrast can be used to direct thepositioning of block copolymer spherical or cylindrical nanodomains withdomain periods of 25 nm or less, corresponding to an areal density of ≧1Tdot/in² as desired for the template fabrication of bit patterned media(BPM). Referring to the drawings, FIG. 1 schematically illustrates afabrication process in accordance with one aspect of the invention.

In FIG. 1, a disc 10 includes a substrate 12 and has a surface pattern14 formed on the substrate. The surface pattern includes a chemicalcontrast surface pattern having a plurality of regions 16 in or on asurface 18. The regions 16 serve as alignment features for subsequentlydeposited nanostructures. While only a few regions 16 are shown in FIG.1 for clarity, it will be appreciated that many more regions 16 may beused in a practical device. The regions and surface have differentaffinities for material that are to be subsequently deposited on thesubstrate, and serve to direct the position and/or orientation ofnanostructures. The regions 16 can be created by conventionallithography, such as e-beam lithography, nanoimprinting,extreme-ultraviolet (EUV) lithography, 193 mn lithography, 248 nmlithography, X-ray lithography, etc.

The half-pitch of the surface pattern 14 can be, for example, tens tohundreds of nanometers. In this example, the regions 16 have asubstantially circular shape in the plane of the surface 18. The regions16 are also referred to as dots.

A self-assembled material is used to fabricate a pattern 20, whoselong-range order and positional accuracy is directed by surface pattern14. In one example, the self-assembled pattern is fabricated using blockcopolymers. The components of the block copolymer will positionthemselves on the surface of the substrate in a pattern that is directedby the chemical contrast pattern of the substrate. One domain of theblock copolymer can be removed to leave the domains 22 in the pattern20. In one example, the remaining domains 22 have a substantiallyspherical shape.

The period ratio between substrate pattern and block copolymer patterncan vary in a range from 1:1 to 10:1. In addition, the lattice structurein substrate chemical contrast pattern is not necessarily the same asthat in the block copolymer pattern. Furthermore, the chemical contrastpattern need not be periodic.

In one example, the size of the alignment dots 16 is smaller than thesize of the block copolymer domain 22 when measured in a lateraldirection, and the volume of the alignment dots is much smaller thanthat of the block copolymer domains.

FIG. 2 is a schematic representation of a block copolymer 30. The blockcopolymer includes a major component 32 and a minor component 34.

FIG. 3 is a cross-sectional view of a portion of a chemically patternedsubstrate 40. A polymer brush layer 42 is formed on a surface 44 of thesubstrate. In this example, openings 46, 48 are formed in the polymerbrush layer. The substrate is formed of a material having an affinity toa first component of a block copolymer, and the polymer brush layer 42is formed of a material having an affinity to a second component of theblock copolymer. When the block copolymer is subsequently applied to thesubstrate, the positions of the domains of the block copolymer will becontrolled by the affinities of the block copolymer components with thesubstrate and the polymer brush layer. The example of FIG. 3 includes aconcave substrate pattern.

FIG. 4 is a cross-sectional view of a portion of a chemically patternedsubstrate 50. A polymer brush layer 52 is formed on a surface 54 of thesubstrate. In this example, nanoposts 56, 58 are formed on the polymerbrush layer. The polymer brush layer is formed of a material having anaffinity to a first component of a block copolymer, and the nanopostsare formed of a material having an affinity to a second component of theblock copolymer. When the block copolymer is subsequently applied to thesubstrate, the positions of the domains of the block copolymer will becontrolled by the affinities of the block copolymer components with thepolymer brush layer and the nanoposts. The example of FIG. 4 includes aconvex substrate pattern.

In the examples described herein, the polymer brush layer can becomprised of polystyrene (for copolymers with polystyrene as the majorblocks). In the example of FIG. 4, the nanoposts can be comprised ofSiO_(x) or various metals, such as tantalum, chromium, titanium, etc.

To form the pattern, a block copolymer can be deposited on the patternedsurface via spin-coating from a dilute solution in general solvents liketoluene, forming monolayered spheres (for sphere-form block copolymers)or lying-down cylinders (for cylinder-form block copolymers), and onedomain of the block copolymer can be removed, using one of several knowntechniques, to leave a plurality of nanostructures in the form of dots(or holes) or lines (or trenches).

Block copolymer nanostructures can be used to form structures havinghalf-pitch domain sizes in the order of about 5 nm to about 50 nm.However, these block copolymer nanostructures usually lack long-rangeorder. In one aspect, this invention addresses the poor long-range orderissue by using a substrate having a surface pattern with a chemicalcontrast to promote long-range order in block copolymer nanostructures.

The block copolymer can include two organic blocks (e.g.,polystyrene-block-polymethylmethacrylate), or one organic block and oneinorganic block (e.g., polystyrene-block-polydimethylsiloxane). One ofthe domains can be removed by UV degradation followed by a wet rinse.For example, upon UV exposure, polymethyhnethacrylate is degraded whilepolystyrene is cross-linked. In another example, oxygen plasma can beused to remove organic components. Polydimethylsiloxane has goodresistance to oxygen plasma.

The substrate pattern with chemical contrast and customized patternlayout can be used to direct the positioning of self-assemblednanodomains with domain periods of 25 nm or less (≧2 Tdot/in²). Thissubstrate chemical pattern can be generated by various advancedlithographic techniques, such as e-beam, nanoimprint, EUV, 193 nm, 248nm, X-ray, etc. Although block copolymers are used as examples here, theself-assembled material is not limited to block copolymers, and it canbe any self-assembling materials with at least two chemically distinctcomponents, e.g., chemically functionalized nanoparticles and nanotubes.In a chemically functionalized nanoparticle, besides the organicnanoparticle inner core, there is an outer shell comprised of organicpolymer chains which have a distinct chemical property compared with theinner core. One example of a chemically functionalized nanoparticle is:3-aminopropyl-(3-oxobutanoic acid) functionalized silica nanoparticle.

FIGS. 5, 6 and 7 are schematic representations of substrate dot patternswith various periodic lattice structures, where Ls is the period (i.e.,the distance between alignment dots) in substrate pattern, Lsx is theperiod in an X direction, and Lsy is the period in a Y direction of aCartesian co-ordinate system.

FIG. 5 shows a hexagon pattern of alignment dots positioned such thatLsy=0.866 Lsx. FIG. 6 shows a stagger pattern of alignment dotspositioned such that Lsy=Lsx. FIG. 7 shows a square pattern of alignmentdots positioned such that Lsy=Lsx.

The period of the substrate pattern is not necessarily equal to thedomain period (1×) in a natural block copolymer pattern, which ishelpful to release the pressure of conventional lithographic technologyused to generate the substrate pattern, for example by e-beamlithography or optical lithography. The natural pattern ofself-assembled materials refers to the self-assembled nanostructureformed without the guidance of external fields, such as a substratetopographic pattern or chemical contrast pattern. With a methoddescribed here, only a sparse substrate pattern (e.g., chemicalcontrast) needs to be generated by conventional lithography, which willbe used to direct a dense self-assembled pattern. Thus, self-assemblyreleases the resolution pressure of conventional lithography.

The pattern multiplication (i.e., the ratio of substrate pattern periodand block copolymer pattern period) ranges from about one to about 10.For example, the ratio of 10 can be used if a single grain of 10×10block copolymer domains can be typically formed in a natural blockcopolymer nanopattern without any surface guidance and thus in the formof multi-grain structures.

Such a pattern multiplication is useful for patterned media fabricationhaving an areal dots density of 1-2 Tdot/in² and beyond. The patterningresolution of this method is only limited by the properties of availableself-assembling materials, which have half-pitch dimensions of about 4mn to about 50 nm for block copolymers, about 3 nm to about 10 nm fornanoparticles, and about 1 nm to about 5 nm for nanotubes, correspondingto areal densities of 1-50 Tdot/in².

FIGS. 8, 9 and 10 are schematic representations of block copolymerpatterns directed by periodic substrate patterns with same or differentlattice structures.

FIG. 8 shows a pattern of nanostructures formed on a substrate havingalignment dots at the positions indicated by item number 60. Thealignment dots are positioned such that Lsy=0.866 Lsx. FIG. 8 shows ahexagonal pattern of alignment dots with 3 times (3×) multiplication,wherein Ls=nLo(±10%), for n=1,2, . . . , 10, and where Lo is the periodin a natural (i.e., undirected) block copolymer pattern. However, thepattern of alignment dots in FIG. 8 is not limited to a 3×multiplication.

FIG. 9 shows a pattern of nanostructures formed on a substrate havingalignment dots at the positions indicated by item number 62. Thealignment dots are positioned such that Lsy=Lsx. FIG. 9 shows a staggerpattern of alignment dots with 3× multiplication, wherein Ls=nLo(±10%),for n=1,2, . . . , 10. However, the pattern of alignment dots in FIG. 9is not limited to a 3× multiplication.

FIG. 8 shows a pattern of nanostructures formed on a substrate havingalignment dots at the positions indicated by item number 64. Thealignment dots are positioned such that Lsy=Lsx.

FIG. 10 shows a square pattern of alignment dots with 4 times (4×)multiplication, wherein Ls=2 nLo(±10%), for n=1, 2, . . . , 5. However,the pattern of alignment dots in FIG. 10 is not limited to a 3×multiplication.

In the structures of FIGS. 8, 9 and 10, a 10×10 natural latticestructure is assumed to be obtainable in a block copolymer patternwithout any substrate guidance.

The lattice structure of the substrate pattern can also be differentfrom that of naturally self-assembled structures. For example, substratepatterns with hexagon, stagger, or square array are all able to alignblock copolymer spherical/cylindrical domains with a naturally hexagonlattice. Furthermore, the substrate pattern need not be periodic, aslong as it can direct long-range ordering of block copolymer domainstructures by pinning some block copolymer nanodomains to the underlyingsubstrate at some spots.

FIG. 11 is a schematic representation of a block copolymer patterndirected by a non-periodic substrate pattern having alignment dots atthe positions indicated by item number 66. In this example, the averagedimension for Ls is <Ls>, and <Ls> is in a range from about 2 Lo toabout 10 Lo.

The substrate pattern can be created by optical lithography. A substratehaving a chemical contrast surface can include alternatinghydrophobic/hydrophilic regions or alternating polar/non-polar regionshaving a distinct affinity to distinct blocks in the copolymer.

Self-assembled nanodot arrays can be directed by a substrate chemicalpattern with pattern pitches that are much larger than the pitches ofthe nanodot array. By using a carefully designed self-assembly system, aspherical block copolymer self-assembled on a substrate hexagon dotpattern with a low-topography chemical contrast, highly addressableblock copolymer dot arrays with 24 nm pitch (1.3 Tdot/in²) directed bysubstrate dot arrays with a periodicity of 24 nm/48 nm/72 nm/96 nm havebeen fabricated. In addition, directed >2 Tdot/in² dot arrays have alsobeen successfully demonstrated. In this example, the dots are arrangedin the array format of FIG. 5.

While others have studied perpendicularly oriented cylindrical blockcopolymers, a neutral surface wetting condition is required to achievedomain orientation perpendicular to both substrate/copolymer interfaceand copolymer/air interface in the case of cylindrical block copolymers.In one aspect, this invention includes a spherical block copolymerwithout the concern of neutral surface wetting to generate anaddressable dot array, which is in thermodynamic equilibrium and thusintrinsically has a low defect density and long-term stability.

FIG. 12 is a photomicrograph of a portion of a patterned media inaccordance with an aspect of the invention. FIG. 12 shows a 1.3 Tdot/in²spherical PS-PDMS block copolymer pattern directed by a hexagonsubstrate pattern with 3× period.

FIG. 13 is a schematic cross-sectional view of a portion of a patternedmedia similar to that shown in FIG. 12. In the example of FIG. 13, asubstrate 70 with a chemically contrasting surface 72 includes a polymerbrush layer 74 and openings 76, 78 in the polymer brush layer. A blockcopolymer 80 is deposited on the chemically contrasting surface. Theblock copolymer includes a plurality of substantially spherical domains82, 84, 86 and 88 of a first component in a second component 90. Domains82 and 88 have an affinity to the substrate and therefore form at thelocations of the openings in the brush polymer layer.

FIG. 14 is a schematic cross-sectional view of the portion of thepatterned media of FIG. 13, after the second component has beensubstantially removed.

In another aspect of the invention, by combining a substrate chemicalpattern with a cylindrical block copolymer, highly ordered dense linepatterns can be fabricated. FIG. 15 is a photomicrograph of acylindrical poly(styrene-dimethyl siloxane) (PS-PDMS) block copolymerpattern directed by a substrate dot pattern. FIG. 15 shows a patternedportion 92 and an unpatterned portion 94, without an underlyingsubstrate pattern. There is no obvious domain orientation in theunpatterned area.

The chemical contrast pattern on the substrate includes a plurality ofdots 96 as shown in FIG. 16. In the pattern of FIG. 16, Ls=n√{squareroot over (3)}Lo(±10%), with n=1,2, . . . , 5, and where Lo is theperiod in natural (i.e., un-directed) block copolymer pattern. When acylindrical block copolymer is deposited on the patterned surface, thecylinders attach to the pattern dots and lie in a directionsubstantially parallel to the patterned surface.

FIGS. 17, 18 and 19 are schematic representations of a cross-section ofa patterned media constructed with a cylindrical block copolymer inaccordance with an aspect of the invention.

FIG. 17 shows a cross-sectional schematic view in cross-track direction.In the example of FIG. 17, a substrate 100 with a chemically contrastingsurface 102 includes a polymer brush layer 104 and openings 106 in thepolymer brush layer. A cylindrical block copolymer 108 is deposited onthe chemically contrasting surface. The block copolymer includes aplurality of substantially cylindrical domains 110, 112 and 114 of afirst component in a second component 116. Domains 110 and 114 have anaffinity to the substrate and therefore form at the locations of theopenings in the brush polymer layer.

FIG. 18 is a schematic cross-sectional view of the portion of thepatterned media of FIG. 17, after the second component has beensubstantially removed.

FIG. 19 is a cross-sectional schematic view of the structure of FIG. 18in the down-track direction.

The block copolymer materials can be any spherical (for a dot array ofnanostructures) or cylindrical (for a dot or line array ofnanostructures) block copolymers with two (or more) highly immiscibleblocks/components, A and B (or more), which can form nanostructures withdomain spacings of 25 nm or less, such aspolystyrene-polymethylmethacrylate (PS-PMMA) (down to ˜20-25 mn),poly(styrene-dimethyl siloxane) (PS-PDMS) (down to ˜10 nm),polystyrene-poly(ethylene oxide) (PS-PEO) (down to ˜15 nm), PS-P2VP(down to ˜12 nm), polystyrene-block-poly(4-vinylpyridine) (PS-P4VP)(down to ˜15 nm), etc.

In one example, the block copolymer nanostructure can be directly usedas a recording media if one component/block includes magnetic elements,such like cobalt, iron, etc.

The self-assembled nanodomains can be integrated into BPM nanoimprinttemplate fabrication including both a regular bit pattern and anon-regular servo pattern as shown in FIG. 20.

FIG. 20 is a schematic representation of a data storage disc template120 in accordance with an aspect of the invention. The disc templateincludes a plurality of tracks 122, only one of which is shown. Eachtrack includes a plurality of data bit areas 124, and a plurality ofservo areas 126. The data bit areas can be fabricated using the processdescribed herein. The servo areas can be fabricated using a lithographicprocess, such as e-beam writing.

FIG. 21 is a process flow diagram illustrating a method for usingdirected self-assembled block copolymer nanostructures in BPM templatefabrication including both a bit pattern and a servo pattern. In thismethod, e-beam writing (EBW) is used to generate a servo pattern in theservo area, and a self-assembly material/process is used to prepare ahigh-density dot array in the bit area. Block 130 shows that the methodstarts by coating a substrate with a thin polymer brush layer. In oneexample, the thin polymer brush layer can have a thickness of about 1 nmto about 10 nm.

The thin polymer brush layer is then coated with a photoresist layerhaving, for example, a thickness of about 20 nm to about 50 nm. Thephotoresist can be patterned using known techniques to include a regulardot pattern (in a bit area) and a non-regular servo pattern (in a servoarea). The photoresist can be patterned using, for example, e-beamlithography, optical lithography, etc. (block 132).

Next, a first evaporation and liftoff process can be used to form afirst hard mask pattern in both the bit and servo areas (using forexample, chromium, tantalum, etc.).

The regular dot pattern in the bit area will be used as a substratepattern to guide a subsequently applied block copolymer pattern and thenon-regular servo pattern in servo area will be used as final servopattern (block 134).

Block 136 shows that the block copolymers are coated and annealed (e.g.,via a thermal/solvent process) to form a highly ordered block copolymerpattern in the bit area directed by the hard mask dot pattern formedpreviously.

Block 138 shows that a second evaporation and liftoff process can beused to form a second hard mask pattern in the bit area, which maypartially overlap with a first hard mask pattern in some spots.

Next, the final hard mask patterns, including a bit pattern (from thesecond hard mask pattern) and a servo pattern (from the first hard maskpattern) are transferred into the substrate (that may be quartz, for anultraviolet (UV) imprint) by etching (or other methods), and all hardmask patterns can be removed by a wet etch, as shown in block 140.

The method illustrated in FIG. 21 can be integrated into the fabricationof BPM nanoimprint master templates including both a bit pattern (havinga regular period, high pattern density, single shape, tightsize/position sigma) and a server pattern (that can be non-periodic orperiodic, with a moderate-to-high pattern density, flexible shape,etc.). A directed self-assembled pattern can be used for the bit regionand an e-beam defined pattern can be used for server region.

The block copolymer can include two organic blocks (e.g.,polystyrene-block-polymethylmethacrylate) or one organic block, oneinorganic block (e.g., polystyrene-block-polydimethylsiloxane). One ofthe domains can be removed by UV degradation followed by a wet rinse.For example, upon UV exposure, polymethylmethacrylate is degraded whilepolystyrene is cross-linked. In another example, oxygen plasma can beused to remove organic components in a hybrid organic-inorganic blockcopolymer. The inorganic block (i.e., polydimethylsiloxane) has goodresistance to oxygen plasma.

In one example, spherical block copolymers are directed by a chemicalcontrast substrate pattern with a customized dot pattern layout togenerate highly ordered dense dot arrays with ultra-high patterndensities.

In another example, cylindrical block copolymers are directed by achemical contrast substrate pattern with a customized dot pattern layoutto generate highly ordered line arrays with high pattern densities.

In one aspect, the highly ordered dot array generated by using thedirected self-assembly method described above can be integrated with ane-beam lithography process to fabricate a full-disc BPM templateincluding both a servo pattern and a bit pattern.

In another aspect, this invention provides apparatus fabricated usingone of the described methods.

While the invention has been described in terms of several examples, itwill be apparent to those skilled in the art that various changes can bemade to the disclosed examples without departing from the scope of theinvention as defined by the following claims. The implementationsdescribed above and other implementations are within the scope of theclaims.

1. A method comprising: providing a substrate having a plurality ofchemically contrasted alignment features; and depositing aself-assembled material on at least a portion of the substrate, whereinthe position and/or orientation of substantially spherical domains ofthe self-assembled material is directed by the alignment features, toform a nanostructure pattern, and wherein the period of the alignmentfeatures is between about 2 times and about 10 times the period of thespherical domains.
 2. The method of claim 1, wherein the alignmentfeatures are smaller than the spherical domains.
 3. The method of claim1, wherein the alignment features are positioned with a period of Ls,and the self-assembled material has a natural period of Lo, andLs=nLo(±10%), for n=1, 2, . . . ,
 10. 4. The method of claim 1, whereinthe alignment features are positioned with a period of Ls, and theself-assembled material has a natural period of Lo, and Ls=n√{squareroot over (3)}Lo(±10%), with n=1, 2, . . . ,
 5. 5. The method of claim1, wherein the alignment features are positioned with an average periodof <Ls>, and the self-assembled material has a natural period of Lo, and<Ls> is in a range from about 2 Lo to about 10 Lo.
 6. An apparatuscomprising: a substrate having a plurality of chemically contrastedalignment features; and a self-assembled material on at least a portionof the substrate, wherein the position and/or orientation ofsubstantially spherical domains of the self-assembled material isdirected by the alignment features, to form a nanostructure pattern, andwherein the average spacing of the alignment features is between about 2times and about 10 times the period of the spherical domains.
 7. Theapparatus of claim 6, wherein the alignment features are smaller thanthe spherical domains.
 8. The apparatus of claim 6, wherein thealignment features are positioned with a period of Ls, and theself-assembled material has a natural period of Lo, and Ls=nLo(±10%),for n=1, 2, . . . ,
 10. 9. The apparatus of claim 6, wherein thealignment features are positioned with a period of Ls, and theself-assembled material has a natural period of Lo, and Ls=n√{squareroot over (3)}Lo(±10%), with n=1, 2, . . . ,
 5. 10. The apparatus ofclaim 6, wherein the alignment features are positioned with an averageperiod of <Ls>, and the self-assembled material has a natural period ofLo, and <Ls> is in a range from about 2 Lo to about 10 Lo.
 11. A methodcomprising: providing a substrate having a plurality of discretechemically contrasted alignment features; and depositing aself-assembled material on at least a portion of the plurality ofchemically contrasted alignment features, wherein the position and/ororientation of substantially cylindrical domains of the self-assembledmaterial is directed by the alignment features, to form a laminarpattern, and wherein the period of the alignment features is betweenabout 2 times and about 10 times the period of the cylindrical domains.12. The method of claim 11, wherein the alignment features are smallerthan the cylindrical domains in at least one direction.
 13. The methodof claim 11, wherein the alignment features are positioned with a periodof Ls, and the self-assembled material has a natural period of Lo, andLs=n√{square root over (3)}Lo(±10%), with n=1, 2, . . . ,
 5. 14. Anapparatus comprising: a substrate having a plurality of discretechemically contrasted alignment features; and a self-assembled materialon at least a portion of the plurality of chemically contrastedalignment features, wherein the position and/or orientation ofsubstantially cylindrical domains of the self-assembled material isdirected by the alignment features, to form a laminar pattern, andwherein the average spacing of the alignment features is between about 2times and about 10 times the period of the cylindrical domains.
 15. Themethod of claim 14, wherein the alignment features are smaller than thecylindrical domains in at least one direction.
 16. The method of claim14, wherein the alignment features are positioned with a period of Ls,and the self-assembled material has a natural period of Lo, andLs=n√{square root over (3)}Lo(±10%), with n=1, 2, . . . ,
 5. 17. Amethod comprising: forming a first plurality of spaced dots in a servoarea of a substrate; using a lithographic process to form a secondplurality of spaced dots in a bit area of a substrate; and depositing aself-assembled material on at least a portion of the bit area, whereinthe position and/or orientation of domains of the self-assembledmaterial is directed by the second plurality of spaced dots, to form ananostructure pattern in the bit area.
 18. The method of claim 17,wherein the step of using a lithographic process to form a secondplurality of spaced dots in a bit area of a substrate are implemented bycoating a substrate with a polymer brush layer and patterning thepolymer brush layer.
 19. The method of claim 17, wherein the domains ofthe self-assembled material comprise spherical domains.
 20. The methodof claim 17, wherein the domains of the self-assembled material comprisecylindrical domains and the nanostructure pattern comprises a laminarpattern.